近日，美国麻省理工学院Chiang, Yet-Ming团队研究了电化学腐蚀伴随着固体电解质中枝晶的生长。这一研究成果于2026年3月25日发表在《自然》杂志上。

使用金属负极的固态电池，其充电速率、循环性能及安全性常受限于枝晶生长，而枝晶的生长取决于电化学驱动力与力学驱动力的耦合作用。此前的研究普遍认为，枝晶会在电镀诱导应力达到固体电解质断裂应力时发生扩展。

研究组表明，枝晶在远低于该阈值的应力下即可扩展。通过原位双折射显微术，研究组直接测量了石榴石型高稳定性固体电解质Li_6.6La₃Zr_1.6Ta_0.4O₁₂中枝晶生长周围的应力分布。电镀诱导应力存在于整个枝晶生长过程中，且对于生长最慢的枝晶，该应力接近其力学断裂应力。

随着电流密度与枝晶生长速率提高，伴随枝晶生长产生的应力反而降低——枝晶在比纯机械加载条件下低75%的应力水平下即可扩展。对高电流下扩展枝晶进行的冷冻扫描透射电子显微术分析显示，电解质会分解形成新物相，并伴随净摩尔体积收缩。通过理解并调控不稳定性伴随的物相转变本质，这种电化学诱导的脆化模式有望被抑制。

附：英文原文

Title: Electrochemical corrosion accompanies dendrite growth in solid electrolytes

Author: Fincher, Cole D., Gilgenbach, Colin, Roach, Christian, Osmundsen, Rachel, Penn, Aubrey, Thouless, Michael D., Carter, W. Craig, Sheldon, Brian W., LeBeau, James M., Chiang, Yet-Ming

Issue&Volume: 2026-03-25

Abstract: Charging rates, cycling performance and safety of solid-state batteries using metal negative electrodes are often limited by dendrites1,2,3, the growth of which depends on coupling between electrochemical and mechanical driving forces. Previously, it has been assumed that dendrites propagate when plating-induced stresses reach the fracture stress of the solid electrolyte. Here we show that dendrites can propagate at far lower stresses. Using operando birefringence microscopy4, we directly measure stresses around growing dendrites in garnet Li6.6La3Zr1.6Ta0.4O12, a highly stable solid electrolyte5,6,7. Plating-induced stresses are present throughout growth and approach the mechanical fracture stress for the slowest-growing dendrites. As current densities and dendrite velocities increase, the stresses accompanying dendrite growth surprisingly decrease, with dendrite propagation occurring at stresses up to 75% lower than under mechanical load alone. Cryogenic scanning transmission electron microscopy (STEM) of dendrites propagated at high current reveals electrolyte decomposition to new phases, associated with which is a net molar volume contraction. The electrochemically induced mode of embrittlement may be mitigated through understanding and control of the nature of phase transitions accompanying instability.

DOI: 10.1038/s41586-026-10279-z

Source: https://www.nature.com/articles/s41586-026-10279-z